Beyond the sky

From awe-inspiring auroras to disrupted power grids, space weather can have a huge impact on Earth. With experienced forecasters on the lookout 24/7, the Met Office’s Space Weather Centre makes sure the UK is ready to act, whatever happens.

Space weather refers to the impact on Earth of solar flares, solar radiation storms and coronal mass ejections (CMEs): huge outbursts of energy and charged particles. CMEs can pierce Earth’s magnetic shield and cause geomagnetic storms and disturbances in the upper atmosphere. These, in turn, can stop radio and satellite communications from being reflected back down to Earth and can also induce currents in the ground that have the potential to damage the national grid.

As our society is increasingly reliant on technology in almost every aspect of life, knowing when these phenomena might affect us is vital to safeguarding key infrastructure. And that’s where the Met Office Space Weather Centre, which marked its second anniversary in October 2016, comes into its own. Mark Gibbs, Head of Space Weather, explains how the centre has developed over the last three years:

“Space weather forecasting is very immature compared with terrestrial weather forecasting. But new knowledge is being generated all the time – which means we’re constantly bringing more capabilities into our service.”

Underpinning UK resilience

Just as the Met Office supports the aviation industry and transport network with customised terrestrial weather services, the Met Office Space Weather Centre is also working to tailor forecasts to specific industries. For example, we help operators of geostationary satellites, which are commonly used for observing the weather and transmitting communications yet can experience upsets caused by strong solar winds.

“We’re getting particularly strong solar wind at the moment,” says Mark. “So although there haven’t been any headline grabbing CMEs this solar cycle, it’s actually been quite a challenging period for geostationary satellite operators. We’re trying to better understand their needs and we are getting to the point of offering tailored forecasts and telephone briefings for them ahead of their key manoeuvres.”

Looking for the Northern Lights

There is also a sunnier side to space weather. CMEs and strong solar winds are what cause the Aurora borealis. This spectacular natural phenomenon is sometimes visible as far south as the UK – although it is usually associated more with Scandinavia and the Arctic. The Met Office will be launching an Aurora borealis forecast model this summer, ready for the autumn season when their occurrence becomes more likely.

Mark explains that the model will provide forecasts 30 minutes ahead of visible aurora and will feature on the Met Office’s public web pages.

“We always get spikes in interest in our website when there’s visible aurora around. Out of all space weather, it’s what really interests people – it’s just something everyone wants to see, me included.”

Shared expertise

As the UK’s forecasting capability develops and diversifies, the Met Office Space Weather Centre continues to work closely with its US counterpart, the National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Centre.

In the early days of the Met Office Space Weather Centre, NOAA was something of a mentor, providing training to get the Met Office’s space weather forecasting off the ground. Now the two partners have equal skill and capability when it comes to creating forecasts – and they maintain a constant dialogue to interpret shared data.

Leaders in the field

The Met Office Space Weather Centre is the only centre outside the USA that’s in operation 24/7 manned by expert forecasters. As one of the global pioneers in this area, it also provides forecasts to countries with varying levels of space weather forecasting capability. For example, the Met Office works with the Swedish meteorological service to provide the government and key infrastructure with warnings about upcoming solar activity.

Other countries work with the Met Office to fill in gaps in their own services. One of these is South Africa, which does have a solar activity forecasting service, but it’s only manned during normal working hours. So, every morning, the Met Office briefs them on what’s happened overnight and any developing themes for the week ahead.

Mark points out that this approach is much the same as the Met Office’s terrestrial weather services. “It’s about sharing knowledge. It never stands still – and we’ve still got so much to learn.”

Reaching new heights

As the organisation responsible for managing the UK’s space weather risk, the Met Office is playing a key role in the development of a new solar observation spacecraft.

Currently, space weather forecast models use data provided by a spacecraft that just gives a head-on view of the sun. While this is essential for observing whether a CME is on a collision course with Earth, we can’t tell the speed accurately from it. As potential power-grid disrupting CMEs can take anywhere from 15 hours to 5 days to arrive, having an accurate picture of how fast they’re travelling is vital for infrastructure operators to put risk mitigation measures in place.

A fresh perspective

This observational gap could soon be filled. The Met Office has been instrumental in leading the development of a concept for a satellite mission to L5 – a point in space that will give a profile view of CMEs as they travel towards Earth. This will enable space weather forecasters to determine how fast a CME is moving – and will feed into more accurate forecasts about when and how earth could be affected.

“We hope that the L5 Mission will enable us to see a CME travelling all the way from the sun to the Earth”, explains Mark Gibbs. “So if our initial estimates of when it will arrive are inaccurate we can make corrections as it gets closer. It’s like terrestrial weather forecasting in that way – we update our longer range forecasts so they become more accurate with time.”

The L5 Mission concept has now been taken on by the European Space Agency, after significant investment from the UK and other EU member states. As the mission develops, the Met Office will take a leading role in planning what observational equipment needs to be on board.